Recently, many carbon-based materials have been studied and used in various products such as thermoplastic resin compositions, secondary batteries, solar cells, display materials, electronic materials, etc. or technical fields. For example, to further improve capacity or electrical characteristics of secondary batteries or solar cells, use of carbon nanotubes, derivatives thereof, etc. has been considered and tried, and to further improve characteristics of various semiconductor devices or display devices, application of carbon-based nanomaterials such as graphene, derivatives thereof, etc. has been tried. In addition, for the purpose of improving mechanical properties of thermoplastic resin compositions or providing them with new properties such as electrical conductivity, etc., use of various carbon-based materials has been tried.
However, in order to achieve desired physical properties by applying carbon-based materials such as carbon nanotubes, graphene, carbon black, fullerene-based materials or derivatives thereof, etc. to various fields, it is required to uniformly disperse these carbon-based materials at high concentrations in other various media including aqueous solvents. For example, to further improve electrical properties of a secondary battery by using a conductive material including carbon nanotube, etc., it is necessary to uniformly disperse these carbon-based materials at high concentrations in media such as aqueous solvents, etc.
However, since most carbon-based materials such as carbon nanotubes, graphene, fullerene-based materials, etc. are generally composed of carbon-carbon bonds, it is difficult to uniformly disperse these carbon-based materials at high concentrations in media in many cases. For this reason, there has been a limitation that it is difficult to take advantages of the carbon-based materials. In order to solve this problem, use of dispersing agents for more uniform dispersion of high concentrations of carbon-based materials in various media has been considered.
However, dispersing agents which have been previously known or studied did not sufficiently disperse carbon-based materials according to the type of media, or must be used in a large amount for effective dispersion of the carbon-based materials. Moreover, the previously known dispersing agents have the disadvantage of requiring very high production costs because their raw materials are expensive or a complex preparation process is required.
For this reason, there is a continuous demand for a novel dispersing agent which is able to uniformly disperse a variety of carbon-based materials such as carbon nanotubes, graphene or fullerene-based materials at high concentrations in various media, for example, environmentally friendly aqueous solvents, even though a relatively small amount thereof is used, and which can be obtained at lower costs by a simpler preparation process.